Re: [PATCH] Allow sequential read to start anywhere in a zone (option offset), and have a span smaller than a zone (option size).

[Damien Le Moal <Damien.LeMoal@wdc.com>]

On 2020/05/16 1:22, plabat@micron.com wrote:
> From: Pierre Labat <plabat@micron.com>
> 
> Allow sequential read to start anywhere in a zone (option
> offset), and have a span smaller than a zone (option size).>
> A use case is a Key Value Store reading a set of keys or values
> starting somewhere in a zone.
> 
> Signed-off-by: Pierre Labat <plabat@micron.com>

This looks OK to me.

Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>

> ---
>  zbd.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/zbd.c b/zbd.c
> index 8dc3c39..f1f7c5c 100644
> --- a/zbd.c
> +++ b/zbd.c
> @@ -262,7 +262,8 @@ static bool zbd_verify_sizes(void)
>  
>  			zone_idx = zbd_zone_idx(f, f->file_offset);
>  			z = &f->zbd_info->zone_info[zone_idx];
> -			if (f->file_offset != z->start) {
> +			if ((f->file_offset != z->start) &&
> +			    (td->o.td_ddir != TD_DDIR_READ)) {
>  				new_offset = (z+1)->start;
>  				if (new_offset >= f->file_offset + f->io_size) {
>  					log_info("%s: io_size must be at least one zone\n",
> @@ -278,7 +279,8 @@ static bool zbd_verify_sizes(void)
>  			zone_idx = zbd_zone_idx(f, f->file_offset + f->io_size);
>  			z = &f->zbd_info->zone_info[zone_idx];
>  			new_end = z->start;
> -			if (f->file_offset + f->io_size != new_end) {
> +			if ((td->o.td_ddir != TD_DDIR_READ) &&
> +			    (f->file_offset + f->io_size != new_end)) {
>  				if (new_end <= f->file_offset) {
>  					log_info("%s: io_size must be at least one zone\n",
>  						 f->file_name);
> 


-- 
Damien Le Moal
Western Digital Research